Resistive element apparatus and method

ABSTRACT

A resistive element, a circuit board, and a circuit package, as well as a method of adding a resistive element to a circuit board are described. The resistive element includes a first contact point connected to a capacitor terminal, a second contact point connected to a circuit board plane, and resistive material connected to the first and second contact points. The invention may also include a circuit board with one or more resistive elements, as well as a circuit package, such as an integrated circuit or a discrete bypass capacitor, including one or more resistive elements, applied to an outside surface. The value of resistance for the resistive element can be selected by design to have a predetermined relationship with the equivalent resistance of an associated circuit board and connecting circuitry.

RELATED PATENTS

[0001] This application is related to co-pending application Ser. No.09/946,963; filed on Sep. 06, 2001, titled “Power Delivery System andMethod for Setting Power Delivery System Parameters”, which is commonlyassigned to the assignee of the present invention.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the addition ofresistive elements to physical circuitry. More particularly, the presentinvention relates to resistive elements as individual components, and aselements of circuit boards and circuit packaging, including integratedcircuits, resistors, and capacitors.

BACKGROUND INFORMATION

[0003] As integrated circuit (IC) technology continues to advance, andoperational clocking speeds increase, chips require more power morequickly. The traditional concept behind using capacitors to decouple ICsis to give each IC a localized reservoir of high-frequency energy. Inessence, local capacitors help to “decouple” associated ICs from themain power supply, decreasing the magnitude of high frequency ripple orsag that appears on the main power bus. The bulk decoupling capacitor ona circuit board, in turn, replenishes each of the local capacitors.

[0004] Unfortunately, a capacitor is not an ideal circuit element. Infact, the capacitor is typically modeled as a series circuit, as shownin prior art FIG. 1. Here the equivalent circuit 101 for a motherboardpower supply decoupling capacitor 103, a local bypass capacitor 104, andthe connecting circuitry 102 between them can be seen. The power supplyPS provides power to the equivalent circuit 101, which in turn passesthe power on to the integrated circuit package IC. The equivalentcircuit 101 may include, as modeled in this example, the mother boardcapacitor 103 series elements C_(MB), ESR_(MB), and L_(MB) connected inparallel with the sum of the connecting circuitry 102 series elementsL_(PLNS+SKT) and R_(PLNS+SKT) and the local bypass capacitor 104 serieselements C_(CPKG), ESR_(CPKG), and L_(CPKG)).

[0005] Because a real-world capacitor is not ideal, including bothreactive and resistive operational components, its response totransients varies as a function of frequency. Thus, at low frequencies,the capacitive reactance due to C_(CPKG) is quite high, dominating theequivalent impedance. As the frequency increases, the capacitivereactance due to C_(CPKG) decreases at a rate of about 20 dB/decade,while the inductive reactance due to L_(CPKG) increases by the sameamount. At the self-resonant frequency (SRF), or 1/{square root}{squareroot over (L_(CPKG)C_(CPKG))}, where the capacitive and inductivereactances are equal but opposite in phase, the impedance of thecapacitor 104 is simply equivalent to the equivalent series resistancefor the capacitor, or ESR_(CPKG). Above the SRF, the equivalentimpedance increases, as the inductive reactance due to L_(CPKG)dominates.

[0006] In addition, when a capacitor is placed on a circuit board, theinductance of the traces and other connecting circuitry (e.g.,L_(PLNS+SKT)) between the capacitor and the associated chip furtheraffects chip performance at high clock speeds. The bypass element 104,and the connecting circuitry (traces) 102 that lead to it, form acurrent loop which operates as an antenna for transmitting radiofrequency interference generated by fast transients. Thus, bypasscapacitors can do their job most efficiently only if mounted in closeproximity to the associated chip pins that draw transient currents.

[0007] In addition to low series inductance L_(CPKG) in a capacitor,it's usually desirable to have a low effective series resistance(ESR_(CPKG)), which goes hand-in-hand with a low dissipation factor.However, sometimes a very low ESR_(CPKG) can provoke unexpected problemsin the form of resonance, especially when the value of ESR_(CPKG) is notmatched to the sum of R_(PLNS+SKT) and ESR_(MB), and when(L_(PLNS+SKT)+L_(MB))/(R_(PLNS+SKT)+ESR_(MB))>>C_(CPKG)*ESR_(CPKG). Whenrepetitive pulses excite the resonator formed by a low equivalent seriesresistance capacitor and the motherboard, high-amplitude ringing canresult, producing an exceedingly noisy supply bus. The typical solutionis to place electrolytic capacitors across the bus to damp the ringing,which is costly and uses a large amount of circuit board real estate. Abetter solution would be to somehow increase the series resistance ofthe bypass capacitor ESR_(CPKG), without adding additional capacitanceor inductance.

[0008] Thus, there is a need in the art to provide additional seriesresistance for bypass capacitors, connected in parallel with theequivalent series resistance of the associated circuit board. Addingthis type of series resistance, possibly in the form of a separateresistive element, should be accomplished at low cost, withoutsubstantially increasing the inductive reactance of the equivalentcircuit. The amount of series resistance added should also beselectable, in accordance with what is necessary to dampen the resonantfrequency response of the equivalent circuit between the associatedpower supply and integrated circuit package. There is also a need in theart for a method to add series resistance to the equivalent circuit, asdescribed above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1, previously described, is a prior art schematic diagram ofan equivalent circuit for a circuit board connected to a bypasscapacitor;

[0010]FIG. 2 is a schematic diagram of an equivalent circuit for acircuit board connected to a capacitor, including an added resistiveelement, according to the present invention;

[0011]FIG. 3 is a side, cut-away view of a circuit board connected to acapacitor and a resistive element according to the present invention;

[0012]FIG. 4 is side, cut-away view of an alternative embodiment of acircuit board connected to a capacitor and a resistive element accordingto the present invention;

[0013]FIG. 5 is a top, plan view of a circuit board connected to acapacitor and a resistive element according to the present invention;

[0014]FIG. 6 is a top, plan view of an alternative embodiment of acircuit board connected to a plurality of capacitors and a correspondingplurality of resistive elements according to the present invention;

[0015]FIG. 7 is a top, plan view of an alternative embodiment of acircuit board connected to a plurality of capacitors and a correspondingplurality of resistive elements according to the present invention; and

[0016]FIG. 8 is a flow chart illustrating a method of adding a resistiveelement to a circuit board according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In the following detailed description of the invention, referenceis made to the accompanying drawings which form a part hereof, and inwhich are shown by way of illustration, and not of limitation, specificembodiments in which the invention may be practiced. In the drawings,like numerals describe substantially similar components throughout theseveral views. The embodiments illustrated are described in sufficientdetail to enable those skilled in the art to practice the invention.Other embodiments may be utilized and derived therefrom, such thatstructural, logical, and electrical circuit substitutions and changesmay be made without departing from the scope of the invention. Thefollowing detailed description, therefore, is not to be taken in alimiting sense, and the scope of the invention is defined only by theappended claims, along with the full range of equivalents to which suchclaims are entitled.

[0018]FIG. 2 is a schematic diagram of an equivalent circuit for acircuit board connected to a capacitor, including an added resistiveelement R_(PL), according to the present invention. It should be notedthat the resistive element R_(PL) has been added in series with thedecoupling capacitor 204 and the connecting circuitry 202. Therefore,the series combination of the resistive element R_(PL), the packagebypass capacitor 204 (which includes series elements of C_(CPKG),ESR_(CPKG), and L_(CPKG)) and the connecting circuitry 202 (which has aseries elements of L_(PLNS+SKT) and R_(PLNS+SKT)) is now connected inparallel with the associated motherboard 203 (which includes the serieselements of C_(MB), ESR_(MB), and L_(MB)). Thus, in this case, the powersupply PS transfers energy to the equivalent circuit which is theparallel combination of the motherboard 203 impedance and the seriesimpedance of the connecting circuitry 202, the capacitor 204, and theresistive element R_(PL). The energy is in turn transferred to the pairof power terminals 274, 276 of the integrated circuit package IC. Theamount of resistance added due to R_(PL) can be adjusted to dampenringing or other effects of resonance arising out of the prior artcircuitry shown in FIG. 1, without necessarily increasing the loop areaof charge flow path, thus not introducing additional inductance.

[0019] Thus, in one embodiment, the invention may be characterized as aresistive element R_(PL) and a bypass capacitor 204 in combination witha circuit board 203 to which is mounted an integrated circuit IC. Themagnitude or value of resistance for the resistive element R_(PL), whichis connected in series with the bypass capacitor 204 across the powerterminals 274, 276 of the IC and the equivalent series resistance of theconnecting circuitry (such as one or more circuit board planes ortraces, or a circuit board power plane) R_(PLNS+SKT), is selected sothat when added to the effective series resistance ESR_(CPKG) of thebypass capacitor 204, the summed series resistance (i.e.,R_(PL)+ESR_(CPKG)) has a predetermined relationship to the effectiveseries resistance ESR_(MB) of the associated circuit board capacitor 203combined with (and connected to) R_(PLNS+SKT) (i.e.,ESRMB+R_(PLNS+SKT)). Thus, the summed series resistanceR_(PL)+ESR_(CPKG) can be selected to be approximately equal to theeffective series resistance of ESRMB+R_(PLNS+SKT).

[0020]FIG. 3 is a side, cut-away view of a circuit board 310 connectedto a capacitor 305 and a resistive element 300 according to the presentinvention. A conventional surface mount capacitor 305 includes a body304 and terminals 306 and 308. The circuit board 310 includes, forexample, a first layer 335, a dielectric layer 332, and a second layer312, such as a power plane layer. The first layer 335 typically includesseveral conductors, such as a first conductor 337 (which may be acombination of copper 334 and plating 342, such as a coating of gold 344over nickel 346) and a second conductor 339 (which may be a combinationof copper 314 and plating 340, such as a coating of gold 344 over nickel346).

[0021] The resistive element 300, which may be a combination of metals,such as a coating of gold 354 over nickel 352, is disposed between thefirst conductor 337 and the via 330. The first conductor 337 may be usedto connect the first contact point 353 of the resistive element 300 tothe terminal 306 of the capacitor 305. Similarly, the via 330 may beused to connect the second contact point 351 of the resistive element300 to the second layer 312. As shown in this example, the terminals306, 308 may be connected to the conductors 337, 339 using solder 326,316, respectively. Conventional solder resist 328 is also shown, and maybe used to prevent the solder 326, 316 from making a direct connectionbetween the terminal 306 and the via 330, for example. Using connectionscheme shown, the current 348 that travels from the capacitor terminal306 to the second layer 312 is forced through the resistive element 300,which has the desired effect of introducing a resistance in series withthe impedance presented by the capacitor 305 with respect to theassociated power supply and integrated circuit, as shown in FIG. 2.Forcing the current 348 to double back on itself also serves to reducethe effective inductance of the capacitor 305. The mutual inductancecurrent cancellation effect is maximized by ensuring that the body ofthe capacitor 305 is attached as closely to the surface of the circuitboard 310 as is practical.

[0022] The series resistance provided by the resistive element 300 canthus be added without introducing relatively large amounts of effectiveinductance, such as would be inherent in the circuitry used to connect astandard surface mount resistor in series with the capacitor 305.Attempting to employ conventional surface mount resistors in thisapplication, such as those provided in the commonly available 0612 and0805 form factors, would indeed increase the series resistance, but willtypically also lead to an intolerable increase in the effectiveinductance L_(CPKG) (e.g., 3 or 4 times). Another problem with such animplementation is that 0612 and 0805 resistors are often unavailable inthe 10-100 milliohm range.

[0023] The resistive element 300 may comprise one or more resistivematerials, each of which may in turn include one or more resistivecomponents, such as the gold over nickel combination shown in FIG. 3.However, as can be seen in FIG. 4, which is a side, cut-away view of analternative embodiment of a circuit board connected to a capacitor and aresistive element according to the present invention, the resistiveelement 400 can also be a conductive epoxy. Thus, the resistive materialof the resistive element 400 may include one or more metals, aconductive epoxy, a ceramic, and/or a resistive film, or a combinationof these, including a conductive metal oxide, a glass, a solvent, apolymer, nickel, chromium, tantalum, silicon monoxide, cobalt, alumina,sapphire, quartz, berillium, palladium, carbon, platinum, ruthenium,rhodium, and gold, further including various thin and thick filmresistor materials, such as tantalum oxynitride, tantalum nitride,nichrome, silver palladium, platinum, ruthenium, rhodium, gold, andtantalum-modified tin oxide.

[0024] As shown in FIG. 4, a conventional surface mount capacitor 405may include a body 404 and terminals 406, 408. The circuit board 410 mayinclude, for example, a first layer 435, a dielectric layer 432, and asecond layer 412, such as a power plane layer. The first layer 435typically includes several conductors, such as a first conductor 437(which may be a combination of copper 434 and plating 442) and a secondconductor 439 (which may be a combination of copper 414 and plating440).

[0025] The resistive element 400, which may include a conductive epoxy,or any of several other resistive materials, as described above, isdisposed between the first conductor 437 and the via 430. The firstconductor 437 may be used to connect the first contact point 453 of theresistive element 400 to the terminal 406 of the capacitor 405.Similarly, the via 430 may be used to connect the second contact point451 of the resistive element 400 to the second layer 412. As shown inthis example, the terminals 406, 408 may be connected to the conductor437, 439 using solder 426, 416, respectively. Conventional solder resist428 is also shown, and may be used to prevent the solder 426, 416 frommaking a direct connection between the first trace 437 and the via 430,for example. Using this type of connection scheme, the current 448 thattravels from the capacitor terminal 406 to the second layer 412 isforced through the resistive element 400, which has the desired effectof introducing a resistance in series with the impedance presented bythe capacitor 405 with respect to the associated power supply andintegrated circuit, as shown in FIG. 2. As mentioned above, care must betaken so that the thickness of the resistive element 400 does not raisethe body of the capacitor 405 away from the surface of the circuit board410 to which it is attached. This is required to control and minimizethe effective L_(CPKG) resulting from the addition of R_(PL). Relativelythick resistive elements 400 may raise the body of the capacitor 405,which increases the loop area of the current flow, which in turnincreases L_(CPKG). If design constraints dictate otherwise, alternativeembodiments, discussed below, provide for locating the resistive element400 outside of the capacitor 405 body, rather than in its shadow.

[0026] In this particular case, the resistive element 400 may beconsidered to comprise the conductive epoxy alone, or may include thecombination of the conductive epoxy and the metallic contacts 462, 464,which may also serve as the location of alternate contact points 457,459.

[0027]FIG. 5 is a top, plan view of a circuit board 510 connected to acapacitor 505 and a resistive element 500 according to the presentinvention. In this case, the terminal 506 is connected to the trace orpad 537 formed on the layer 535 of the circuit board 510 and the contactpoint 551 of the resistive element 500. As noted above, the firstcontact point 551 may be connected to the terminal 506 of the capacitor505 using solder 526.

[0028] The resistive element 500, in turn, is connected by way of thecontact point 553 to the vias 582, which in turn are connected to thepower plane layer 512. Use of multiple vias 582 is preferred, as thepractice reduces the inductance which may be added along the length L ofthe resistive element 500. The terminal 508 of the capacitor 505 isconnected (typically using solder 516) to a surface trace or a plane539, which is in turn connected to the circuit package 570 by way of theterminal 572. The use of multiple terminals 572 is also preferred, ifpossible, as the practice also serves to reduce circuit inductance.

[0029] As noted above, the resistive element 500 may comprise any ofseveral resistive materials, singly or in combination. The amount ofresistance provided by the resistive element is selectable by design.For example, as can be seen in FIG. 4, the volumetric displacement V ofthe resistive element 400 can be measured as it is dispensed onto thecircuit board layer 435. In fact, it may even be possible to probe thecontact points 451, 453 of the resistive element 400 during thedispensing operation to obtain a more precise amount of resistancebetween the terminal 406 and the via 430. Alternatively, as can be seenin FIGS. 3, 5, and 6, the length L, width W, and thickness T of theresistive element 300, 500, 600 can be selected to provide apredetermined resistance between the contact points. For example, usinga bimetallic gold over nickel configuration for the resistive element500, with a nickel thickness of about 0.4 microns, and a gold thicknessof about 0.08 microns (total thickness T=0.48 microns), with each layerhaving a length of about 400 microns and a width of about 3050 microns,the resistance of the element 500 will be about 14 milliohms. The totalthickness of the bimetallic resistive element in this configuration willgenerally range from about 0.05 microns to about 2.5 microns, dependingon the length L and width W, which may vary from about 10 to 1000microns (for W) and from about 10 to 5000 microns (for L).

[0030] Many different embodiments of the invention may be devised. Forexample, FIG. 6 is a top, plan view of an alternative embodiment of acircuit board 610 connected to a plurality of capacitors 605 and acorresponding plurality of resistive elements 600, 690 according to thepresent invention. In this case, the terminal 606 is connected to thepad or trace 637 formed on the layer 635 of the circuit board 610 andthe contact point 651 of the resistive element 600. As noted above, thefirst contact point 651 may be connected to the terminal 606 of thecapacitor 605 using solder 626.

[0031] The resistive element 600, in turn, is connected by way of thecontact point 653, to the vias 682, which in turn are connected to thepower plane layer 612. The resistive element 600 may comprise any ofseveral resistive materials, singly or in combination, and the use ofmultiple vias 682 is encouraged, as noted above. The terminal 608 of thecapacitor 605 is connected (typically using solder 616) to the surfacetrace or plane 639, which is in turn connected to the circuit package670 by way of the terminal 672. The use of multiple terminals 672 isalso preferred, if possible, as the practice also serves to reducecircuit inductance.

[0032] Other capacitors 611 may also be connected to the circuit board610 using terminals 613, 615, and corresponding resistive elements 690,vias 692, pads or traces 693, 691, and solder 696, 697. The capacitors605, 611 may be discrete entities, or formed as a single integrateddevice package 617. It should be noted that the connections to thecapacitors 605, 611 shown in FIG. 6 have been simplified forillustrative purposes. Using commonly available packages of capacitors617, it is likely that connections to the circuit package 670 will makeuse of alternating patterns of vias 682, 692 and resistive elements 600,690. Such a configuration is shown in FIG. 7.

[0033] In this case, a capacitor package 717 and an integrated circuitpackage 770 are attached to a circuit board 710. The capacitor package717 includes a plurality of individual bypass capacitors 711, eachhaving a pair of terminals 713. On one end of each capacitor 711, aterminal 713 may be used to connect the capacitor 711 to a pad 737 onthe circuit board 710, which is in turn connected using vias 727 to apower terminal 772 of the integrated circuit package 770, by way of apower plane 712. Use of multiple terminals 772 is preferred, as thepractice reduces circuit inductance. On the other end of each capacitor711, a terminal 729 may be used to connect to a resistive element 700.The resistive element may then be connected to a ground terminal 743 ofthe integrated circuit package 770 by way of vias 792 and a ground plane733. Use of multiple terminals 792 is also preferred, as the practiceserves to reduce circuit inductance.

[0034] In this case, the resistive elements 700 are located outside ofthe “shadow” of the capacitor package 717, rather than underneath thepackage 717. Placing the resistive elements 700 in this location isuseful when the material used to make the elements 700 is of nonuniformviscosity, or when design constraints require a thick deposition ofresistive element material. Excessive height in the resistive elementsis to be avoided, since the capacitor package 717 to which the elements700 are attached would otherwise be raised significantly off of thesurface of the board 710, increasing the distance between the currentpath through the package 717 and the plane to which the individualcapacitors 711 are connected, serving to increase, rather than reducethe effective inductance of the associated capacitors 711. It shouldalso be noted that the terminals 713 of capacitors 711 not connected toresistive elements 700, as well as the resistive elements 700themselves, are usually connected to their associated planes 712, 733using as many vias 727, 792 as is practical, so as to reduce loopinductive reactance.

[0035] One of ordinary skill in the art will understand that theresistive element of the present invention can be used in applicationsother than for circuit boards and circuit packages, and thus, theinvention is not to be so limited. The illustrations of a resistiveelement 200, 300, 400, 500, 600, and 700, a circuit board 310, 410, 510,610, and 710, and a circuit package 305, 405, 505, 605, and 705 areintended to provide a general understanding of the structure of thepresent invention, and are not intended to serve as a completedescription of all the elements and features of resistive elements,circuit boards, and circuit packages which might make use of thecircuitry and structures described herein.

[0036] Applications which may include the novel resistive element,circuit board, and circuit package of the present invention includeelectronic circuitry used in high-speed computers, device drivers, powermodules, communication circuitry, modems, processor modules, embeddedprocessors, and application-specific modules, including multilayer,multi-chip modules. Such resistive elements, circuit boards, and circuitpackages may further be included as sub-components within a variety ofelectronic systems, such as televisions, cellular telephones, personalcomputers, personal radios, aircraft, and others.

[0037]FIG. 8 is a flow chart illustrating a method 871 of adding aresistive element to a circuit board according to the present invention.The method 871 begins at block 873 with selecting an amount ofequivalent series resistance for a resistive element to be disposed onthe circuit board, which will typically depend on the amount of dampingrequired (or other desired circuit activity induced by insertion of theresistive element R_(PL)) in the equivalent circuit shown in FIG. 2.After the amount of resistance for R_(PL) has been selected, the method871 continues at block 875 with selecting the type of material for theresistive element. As noted above, the resistive element may include oneor more resistive materials, which in turn may each include one or moremetals, a conductive epoxy, a ceramic, and/or a resistive film, or acombination of these, including a conductive metal oxide, a glass, asolvent, a polymer, nickel, chromium, tantalum, silicon monoxide,cobalt, alumina, sapphire, quartz, berillium, palladium, platinum,ruthenium, rhodium, and gold, further including various thin and thickfilm resistor materials, such as tantalum oxynitride, tantalum nitride,nichrome, silver palladium, carbon, platinum, ruthenium, rhodium, gold,and/or tantalum-modified tin oxide.

[0038] The method 871 then continues with fabricating at least onesurface layer of the circuit board, including a pad or trace and a viafor connection to a conductive plane, such as a power plane (block 877)and depositing the resistive element on the surface layer of the circuitboard so as to connect the pad to the via (block 879). Typically,connection is made by using a first contact point of the resistiveelement to make contact with the pad/trace, and using a second contactpoint of the resistive element to make contact with the via.

[0039] Given the wide variety of materials which may be used in thefabrication of a resistive element, the procedure used to deposit theresistive element on the surface layer of the circuit board may vary.For example, according to decision block 881, if the resistive block isnot metal, then depositing the resistive element on the surface layer ofthe circuit board so as to connect the pad to the via may furtherinclude screening the resistive element onto the layer of the circuitboard, which is a process more appropriate to the installation of thickfilm resistors. However, if the resistive element includes metal, suchas gold over nickel, then depositing the resistive element on the layerof the circuit board so as to connect the pad to the via may includeplating the resistive element onto the surface layer of the circuitboard. The method ends at block 887.

[0040] The apparatus and method of the invention provides an additionalseries resistance which can be used in conjunction with bypasscapacitors, circuit boards, and circuit packages, connected in parallelwith the equivalent series resistance of the associated circuit board.The addition of series resistance, in the form of a resistive element,is accomplished in a relatively simple fashion, without undulyincreasing connecting circuitry inductive reactance. The amount ofseries resistance is also easily selectable, in accordance with what isnecessary to dampen the effects of various resonant frequencies whichmay be present.

[0041] Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art appreciate that anyarrangement which is calculated to achieve the same purpose may besubstituted for the specific embodiment shown. This disclosure isintended to cover any and all adaptations or variations of the presentinvention. It is to be understood that the above description has beenmade in an illustrative fashion, and not a restrictive one. Combinationsof the above embodiments, and other embodiments not specificallydescribed herein will be apparent to those of skill in the art uponreviewing the above description. The scope of the invention includes anyother applications in which the above structures, circuitry, and methodsare used. The scope of the invention should be determined with referenceto the appended claims, along with the full range of equivalents towhich such claims are entitled.

What is claimed is:
 1. A resistive element, comprising: a first contactpoint connected to a capacitor terminal; a second contact pointconnected to a circuit board plane; and a resistive material connectedto the first and second contact points.
 2. The resistive element ofclaim 1, wherein the first contact point is connected to the capacitorterminal using solder, and wherein the second contact point is connectedto the circuit board plane using at least one via.
 3. The resistiveelement of claim 1, wherein the resistive material includes a firstmetal.
 4. The resistive element of claim 3, wherein the first metal isnickel.
 5. The resistive element of claim 3, wherein the resistivematerial includes a second metal.
 6. The resistive element of claim 5,wherein the second metal is gold.
 7. The resistive element of claim 6,wherein the first and second metals have a width of about 10 to about1000 microns, a length of about 10 to about 5000 microns, and a totalthickness of about 0.05 to about 2.5 microns.
 8. The resistive elementof claim 1, wherein the resistive material includes a conductive epoxy.9. The resistive element of claim 1, wherein the resistive materialincludes a resistive component selected from a group consisting of: ametal, a conductive metal oxide, a glass, a solvent, a polymer, nickel,chromium, tantalum, oxynitride, silicon monoxide, cobalt, alumina,sapphire, quartz, berillium, palladium, carbon, platinum, ruthenium,rhodium, and gold.
 10. The resistive element of claim 1, wherein thesecond contact point is connected to the circuit board plane using aplurality of vias.
 11. The resistive element of claim 1, wherein asummed series resistance provided by adding a value of resistance forthe resistive element to an effective series resistance of the capacitoris approximately equal to an effective series resistance of a circuitboard capacitor and a circuit board plane connected to the circuit boardcapacitor.
 12. A circuit board, comprising: a capacitor having aterminal; a power supply plane; and a resistive element including afirst contact point connected to the terminal of the capacitor, a secondcontact point connected to the power supply plane, and a resistivematerial connected to the first and second contact points.
 13. Thecircuit board of claim 12, wherein the first contact point is connectedto the terminal of the capacitor using solder, and wherein the secondcontact point is connected to the power supply plane using at least onevia.
 14. The circuit board of claim 13, wherein the resistive materialincludes a first metal and a second metal.
 15. The circuit board ofclaim 14, wherein the first metal is nickel and the second metal isgold.
 16. The circuit board of claim 12, wherein the resistive materialis selected from a group consisting of: a metal, a conductive metaloxide, a glass, a solvent, a polymer, nickel, chromium, tantalum,oxynitride, silicon monoxide, cobalt, alumina, sapphire, quartz,berillium, palladium, carbon, platinum, ruthenium, rhodium, and gold.17. The circuit board of claim 12, wherein a summed series resistanceprovided by adding a value of resistance for the resistive element to aneffective series resistance of the capacitor is approximately equal toan effective series resistance of a circuit board capacitor and aneffective series resistance of the power supply plane connected to thecircuit board capacitor.
 18. A circuit package, comprising: a circuitelement; a first terminal connected to the circuit element; and a secondterminal connected the circuit element and to a first contact point of aresistive element including a second contact point for connection to apower supply plane.
 19. The circuit package of claim 18, wherein thecircuit element is a capacitor.
 20. The circuit package of claim 18,wherein the circuit element includes at least one transistor.
 21. Thecircuit package of claim 18, wherein the circuit package has an outsidesurface to which the resistive element is attached.
 22. The circuitpackage of claim 18, wherein a summed series resistance provided byadding a value of resistance for the resistive element to an effectiveseries resistance of the circuit element is approximately equal to aneffective series resistance of a circuit board capacitor connected tothe power supply plane added to an effective series resistance of thepower supply plane.
 23. A method fabricating a circuit board,comprising: selecting an amount of equivalent series resistance for aresistive element including a first contact point and a second contactpoint; selecting a type of material for the resistive element;fabricating at least one layer of the circuit board having a pad and avia for connection to a power plane of the circuit board; depositing theresistive element on the layer of the circuit board so as to connect thefirst contact point to the pad and to connect the second contact pointto the via.
 24. The method of claim 23, wherein depositing the resistiveelement on the layer of the circuit board so as to connect the firstcontact point to the pad and to connect the second contact point to thevia further comprises: screening the resistive element onto the layer ofthe circuit board.
 25. The method of claim 23, wherein depositing theresistive element on the layer of the circuit board so as to connect thefirst contact point to the pad and to connect the second contact pointto the via further comprises: plating the resistive element onto thelayer of the circuit board.
 26. The method of claim 23, whereinselecting an amount of equivalent series resistance for a resistiveelement further comprises: selecting a value of resistance for theresistive element such that a summed series resistance provided byadding the value of resistance for the resistive element to an effectiveseries resistance of a first capacitor is approximately equal to aneffective series resistance of a second capacitor attached to thecircuit board added to an effective series resistance of the powerplane.